Techno-Economic and Emissions Assessment of Blue Hydrogen Production from CO2-EOR-Associated Natural Gas

Abstract

Blue hydrogen made from natural gas while capturing and storing most of the CO2 has become a popular idea as a practical stepping stone toward a cleaner energy future. Yet, one potentially valuable integration remains underexplored: linking it directly to CO2-enhanced oil recovery (EOR). In these projects, captured CO2 is injected into mature oil fields to enhance oil recovery, and over time the gas that comes up with the oil ends up containing a lot of that recycled CO2. This "associated" natural gas is often flared, reinjected, or sold as-is with limited carbon optimization, despite its potential to serve as a dedicated feedstock for blue hydrogen production. This creates an intriguing loop for carbon management system while improving resource utilization and infrastructure efficiency. However, there have been few studies which have done a systematic assessment of the economic feasibility, emission performance, and scalability of an integrated approach. This study conducts an integrated techno-economic and emissions assessment of blue hydrogen production from CO2-EOR-associated natural gas, aiming to quantify its cost competitiveness, environmental footprint, and role in accelerating the energy transition. To address key gaps in system integration, feedstock assumptions, emissions accounting, and economic attribution, we develop a unified framework that links CO2 capture from hydrogen reforming, its utilization in EOR for oil recovery, processing of the resulting associated gas as a hydrogen feedstock, and subsequent CO2 recycling or storage. Our methodology links hydrogen production via steam methane reforming (SMR) and autothermal reforming (ATR) with carbon capture, carbon dioxide utilisation in enhanced oil recovery, processing of EOR-associated gas as hydrogen feedstock, and subsequent carbon dioxide recycling and permanent geological storage. The framework draws on published performance data, established engineering correlations, and cost benchmarks to construct a transparent, reproducible model suitable for systematic comparison across pathways and scenarios. The techno-economic assessment estimates capital and operating expenditures for hydrogen production, CO2 capture, compression, transport, and EOR-related infrastructure, and evaluates economic performance using levelized cost of hydrogen (LCOH), carbon abatement cost, and sensitivity analyses with respect to natural gas price, oil price, CO2 retention efficiency, and carbon pricing. In parallel, a lifecycle greenhouse gas emission analysis is conducted to quantify greenhouse gas emissions intensity (kg CO2-eq per kg H2), including upstream methane leakage, process emissions, CO2 permanently stored through EOR, and emissions associated with incremental oil production. The results are compared with conventional blue hydrogen pathways relying on saline aquifer storage and with grey hydrogen benchmarks, providing insight into the conditions under which CO2-EOR-integrated blue hydrogen can deliver both economic and environmental benefits.